xref: /linux/arch/parisc/net/bpf_jit_comp32.c (revision a1c613ae4c322ddd58d5a8539dbfba2a0380a8c0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * BPF JIT compiler for PA-RISC (32-bit)
4  *
5  * Copyright (c) 2023 Helge Deller <deller@gmx.de>
6  *
7  * The code is based on the BPF JIT compiler for RV64 by Björn Töpel and
8  * the BPF JIT compiler for 32-bit ARM by Shubham Bansal and Mircea Gherzan.
9  */
10 
11 #include <linux/bpf.h>
12 #include <linux/filter.h>
13 #include <linux/libgcc.h>
14 #include "bpf_jit.h"
15 
16 /*
17  * Stack layout during BPF program execution (note: stack grows up):
18  *
19  *                     high
20  *   HPPA32 sp =>  +----------+ <= HPPA32 fp
21  *                 | saved sp |
22  *                 | saved rp |
23  *                 |   ...    | HPPA32 callee-saved registers
24  *                 | curr args|
25  *                 | local var|
26  *                 +----------+ <= (sp - 4 * NR_SAVED_REGISTERS)
27  *                 |  lo(R9)  |
28  *                 |  hi(R9)  |
29  *                 |  lo(FP)  | JIT scratch space for BPF registers
30  *                 |  hi(FP)  |
31  *                 |   ...    |
32  *                 +----------+ <= (sp - 4 * NR_SAVED_REGISTERS
33  *                 |          |        - 4 * BPF_JIT_SCRATCH_REGS)
34  *                 |          |
35  *                 |   ...    | BPF program stack
36  *                 |          |
37  *                 |   ...    | Function call stack
38  *                 |          |
39  *                 +----------+
40  *                     low
41  */
42 
43 enum {
44 	/* Stack layout - these are offsets from top of JIT scratch space. */
45 	BPF_R8_HI,
46 	BPF_R8_LO,
47 	BPF_R9_HI,
48 	BPF_R9_LO,
49 	BPF_FP_HI,
50 	BPF_FP_LO,
51 	BPF_AX_HI,
52 	BPF_AX_LO,
53 	BPF_R0_TEMP_HI,
54 	BPF_R0_TEMP_LO,
55 	BPF_JIT_SCRATCH_REGS,
56 };
57 
58 /* Number of callee-saved registers stored to stack: rp, r3-r18. */
59 #define NR_SAVED_REGISTERS	(18 - 3 + 1 + 8)
60 
61 /* Offset from fp for BPF registers stored on stack. */
62 #define STACK_OFFSET(k)	(- (NR_SAVED_REGISTERS + k + 1))
63 #define STACK_ALIGN	FRAME_SIZE
64 
65 #define EXIT_PTR_LOAD(reg)	hppa_ldw(-0x08, HPPA_REG_SP, reg)
66 #define EXIT_PTR_STORE(reg)	hppa_stw(reg, -0x08, HPPA_REG_SP)
67 #define EXIT_PTR_JUMP(reg, nop)	hppa_bv(HPPA_REG_ZERO, reg, nop)
68 
69 #define TMP_REG_1	(MAX_BPF_JIT_REG + 0)
70 #define TMP_REG_2	(MAX_BPF_JIT_REG + 1)
71 #define TMP_REG_R0	(MAX_BPF_JIT_REG + 2)
72 
73 static const s8 regmap[][2] = {
74 	/* Return value from in-kernel function, and exit value from eBPF. */
75 	[BPF_REG_0] = {HPPA_REG_RET0, HPPA_REG_RET1},		/* HI/LOW */
76 
77 	/* Arguments from eBPF program to in-kernel function. */
78 	[BPF_REG_1] = {HPPA_R(3), HPPA_R(4)},
79 	[BPF_REG_2] = {HPPA_R(5), HPPA_R(6)},
80 	[BPF_REG_3] = {HPPA_R(7), HPPA_R(8)},
81 	[BPF_REG_4] = {HPPA_R(9), HPPA_R(10)},
82 	[BPF_REG_5] = {HPPA_R(11), HPPA_R(12)},
83 
84 	[BPF_REG_6] = {HPPA_R(13), HPPA_R(14)},
85 	[BPF_REG_7] = {HPPA_R(15), HPPA_R(16)},
86 	/*
87 	 * Callee-saved registers that in-kernel function will preserve.
88 	 * Stored on the stack.
89 	 */
90 	[BPF_REG_8] = {STACK_OFFSET(BPF_R8_HI), STACK_OFFSET(BPF_R8_LO)},
91 	[BPF_REG_9] = {STACK_OFFSET(BPF_R9_HI), STACK_OFFSET(BPF_R9_LO)},
92 
93 	/* Read-only frame pointer to access BPF stack. Not needed. */
94 	[BPF_REG_FP] = {STACK_OFFSET(BPF_FP_HI), STACK_OFFSET(BPF_FP_LO)},
95 
96 	/* Temporary register for blinding constants. Stored on the stack. */
97 	[BPF_REG_AX] = {STACK_OFFSET(BPF_AX_HI), STACK_OFFSET(BPF_AX_LO)},
98 	/*
99 	 * Temporary registers used by the JIT to operate on registers stored
100 	 * on the stack. Save t0 and t1 to be used as temporaries in generated
101 	 * code.
102 	 */
103 	[TMP_REG_1] = {HPPA_REG_T3, HPPA_REG_T2},
104 	[TMP_REG_2] = {HPPA_REG_T5, HPPA_REG_T4},
105 
106 	/* temporary space for BPF_R0 during libgcc and millicode calls */
107 	[TMP_REG_R0] = {STACK_OFFSET(BPF_R0_TEMP_HI), STACK_OFFSET(BPF_R0_TEMP_LO)},
108 };
109 
hi(const s8 * r)110 static s8 hi(const s8 *r)
111 {
112 	return r[0];
113 }
114 
lo(const s8 * r)115 static s8 lo(const s8 *r)
116 {
117 	return r[1];
118 }
119 
emit_hppa_copy(const s8 rs,const s8 rd,struct hppa_jit_context * ctx)120 static void emit_hppa_copy(const s8 rs, const s8 rd, struct hppa_jit_context *ctx)
121 {
122 	REG_SET_SEEN(ctx, rd);
123 	if (OPTIMIZE_HPPA && (rs == rd))
124 		return;
125 	REG_SET_SEEN(ctx, rs);
126 	emit(hppa_copy(rs, rd), ctx);
127 }
128 
emit_hppa_xor(const s8 r1,const s8 r2,const s8 r3,struct hppa_jit_context * ctx)129 static void emit_hppa_xor(const s8 r1, const s8 r2, const s8 r3, struct hppa_jit_context *ctx)
130 {
131 	REG_SET_SEEN(ctx, r1);
132 	REG_SET_SEEN(ctx, r2);
133 	REG_SET_SEEN(ctx, r3);
134 	if (OPTIMIZE_HPPA && (r1 == r2)) {
135 		emit(hppa_copy(HPPA_REG_ZERO, r3), ctx);
136 	} else {
137 		emit(hppa_xor(r1, r2, r3), ctx);
138 	}
139 }
140 
emit_imm(const s8 rd,s32 imm,struct hppa_jit_context * ctx)141 static void emit_imm(const s8 rd, s32 imm, struct hppa_jit_context *ctx)
142 {
143 	u32 lower = im11(imm);
144 
145 	REG_SET_SEEN(ctx, rd);
146 	if (OPTIMIZE_HPPA && relative_bits_ok(imm, 14)) {
147 		emit(hppa_ldi(imm, rd), ctx);
148 		return;
149 	}
150 	emit(hppa_ldil(imm, rd), ctx);
151 	if (OPTIMIZE_HPPA && (lower == 0))
152 		return;
153 	emit(hppa_ldo(lower, rd, rd), ctx);
154 }
155 
emit_imm32(const s8 * rd,s32 imm,struct hppa_jit_context * ctx)156 static void emit_imm32(const s8 *rd, s32 imm, struct hppa_jit_context *ctx)
157 {
158 	/* Emit immediate into lower bits. */
159 	REG_SET_SEEN(ctx, lo(rd));
160 	emit_imm(lo(rd), imm, ctx);
161 
162 	/* Sign-extend into upper bits. */
163 	REG_SET_SEEN(ctx, hi(rd));
164 	if (imm >= 0)
165 		emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
166 	else
167 		emit(hppa_ldi(-1, hi(rd)), ctx);
168 }
169 
emit_imm64(const s8 * rd,s32 imm_hi,s32 imm_lo,struct hppa_jit_context * ctx)170 static void emit_imm64(const s8 *rd, s32 imm_hi, s32 imm_lo,
171 		       struct hppa_jit_context *ctx)
172 {
173 	emit_imm(hi(rd), imm_hi, ctx);
174 	emit_imm(lo(rd), imm_lo, ctx);
175 }
176 
__build_epilogue(bool is_tail_call,struct hppa_jit_context * ctx)177 static void __build_epilogue(bool is_tail_call, struct hppa_jit_context *ctx)
178 {
179 	const s8 *r0 = regmap[BPF_REG_0];
180 	int i;
181 
182 	if (is_tail_call) {
183 		/*
184 		 * goto *(t0 + 4);
185 		 * Skips first instruction of prologue which initializes tail
186 		 * call counter. Assumes t0 contains address of target program,
187 		 * see emit_bpf_tail_call.
188 		 */
189 		emit(hppa_ldo(1 * HPPA_INSN_SIZE, HPPA_REG_T0, HPPA_REG_T0), ctx);
190 		emit(hppa_bv(HPPA_REG_ZERO, HPPA_REG_T0, EXEC_NEXT_INSTR), ctx);
191 		/* in delay slot: */
192 		emit(hppa_copy(HPPA_REG_TCC, HPPA_REG_TCC_IN_INIT), ctx);
193 
194 		return;
195 	}
196 
197 	/* load epilogue function pointer and jump to it. */
198 	/* exit point is either directly below, or the outest TCC exit function */
199 	emit(EXIT_PTR_LOAD(HPPA_REG_RP), ctx);
200 	emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
201 
202 	/* NOTE: we are 32-bit and big-endian, so return lower 32-bit value */
203 	emit_hppa_copy(lo(r0), HPPA_REG_RET0, ctx);
204 
205 	/* Restore callee-saved registers. */
206 	for (i = 3; i <= 18; i++) {
207 		if (OPTIMIZE_HPPA && !REG_WAS_SEEN(ctx, HPPA_R(i)))
208 			continue;
209 		emit(hppa_ldw(-REG_SIZE * (8 + (i-3)), HPPA_REG_SP, HPPA_R(i)), ctx);
210 	}
211 
212 	/* load original return pointer (stored by outest TCC function) */
213 	emit(hppa_ldw(-0x14, HPPA_REG_SP, HPPA_REG_RP), ctx);
214 	emit(hppa_bv(HPPA_REG_ZERO, HPPA_REG_RP, EXEC_NEXT_INSTR), ctx);
215 	/* in delay slot: */
216 	emit(hppa_ldw(-0x04, HPPA_REG_SP, HPPA_REG_SP), ctx);
217 }
218 
is_stacked(s8 reg)219 static bool is_stacked(s8 reg)
220 {
221 	return reg < 0;
222 }
223 
bpf_get_reg64_offset(const s8 * reg,const s8 * tmp,u16 offset_sp,struct hppa_jit_context * ctx)224 static const s8 *bpf_get_reg64_offset(const s8 *reg, const s8 *tmp,
225 		u16 offset_sp, struct hppa_jit_context *ctx)
226 {
227 	if (is_stacked(hi(reg))) {
228 		emit(hppa_ldw(REG_SIZE * hi(reg) - offset_sp, HPPA_REG_SP, hi(tmp)), ctx);
229 		emit(hppa_ldw(REG_SIZE * lo(reg) - offset_sp, HPPA_REG_SP, lo(tmp)), ctx);
230 		reg = tmp;
231 	}
232 	REG_SET_SEEN(ctx, hi(reg));
233 	REG_SET_SEEN(ctx, lo(reg));
234 	return reg;
235 }
236 
bpf_get_reg64(const s8 * reg,const s8 * tmp,struct hppa_jit_context * ctx)237 static const s8 *bpf_get_reg64(const s8 *reg, const s8 *tmp,
238 			       struct hppa_jit_context *ctx)
239 {
240 	return bpf_get_reg64_offset(reg, tmp, 0, ctx);
241 }
242 
bpf_get_reg64_ref(const s8 * reg,const s8 * tmp,bool must_load,struct hppa_jit_context * ctx)243 static const s8 *bpf_get_reg64_ref(const s8 *reg, const s8 *tmp,
244 		bool must_load, struct hppa_jit_context *ctx)
245 {
246 	if (!OPTIMIZE_HPPA)
247 		return bpf_get_reg64(reg, tmp, ctx);
248 
249 	if (is_stacked(hi(reg))) {
250 		if (must_load)
251 			emit(hppa_ldw(REG_SIZE * hi(reg), HPPA_REG_SP, hi(tmp)), ctx);
252 		reg = tmp;
253 	}
254 	REG_SET_SEEN(ctx, hi(reg));
255 	REG_SET_SEEN(ctx, lo(reg));
256 	return reg;
257 }
258 
259 
bpf_put_reg64(const s8 * reg,const s8 * src,struct hppa_jit_context * ctx)260 static void bpf_put_reg64(const s8 *reg, const s8 *src,
261 			  struct hppa_jit_context *ctx)
262 {
263 	if (is_stacked(hi(reg))) {
264 		emit(hppa_stw(hi(src), REG_SIZE * hi(reg), HPPA_REG_SP), ctx);
265 		emit(hppa_stw(lo(src), REG_SIZE * lo(reg), HPPA_REG_SP), ctx);
266 	}
267 }
268 
bpf_save_R0(struct hppa_jit_context * ctx)269 static void bpf_save_R0(struct hppa_jit_context *ctx)
270 {
271 	bpf_put_reg64(regmap[TMP_REG_R0], regmap[BPF_REG_0], ctx);
272 }
273 
bpf_restore_R0(struct hppa_jit_context * ctx)274 static void bpf_restore_R0(struct hppa_jit_context *ctx)
275 {
276 	bpf_get_reg64(regmap[TMP_REG_R0], regmap[BPF_REG_0], ctx);
277 }
278 
279 
bpf_get_reg32(const s8 * reg,const s8 * tmp,struct hppa_jit_context * ctx)280 static const s8 *bpf_get_reg32(const s8 *reg, const s8 *tmp,
281 			       struct hppa_jit_context *ctx)
282 {
283 	if (is_stacked(lo(reg))) {
284 		emit(hppa_ldw(REG_SIZE * lo(reg), HPPA_REG_SP, lo(tmp)), ctx);
285 		reg = tmp;
286 	}
287 	REG_SET_SEEN(ctx, lo(reg));
288 	return reg;
289 }
290 
bpf_get_reg32_ref(const s8 * reg,const s8 * tmp,struct hppa_jit_context * ctx)291 static const s8 *bpf_get_reg32_ref(const s8 *reg, const s8 *tmp,
292 		struct hppa_jit_context *ctx)
293 {
294 	if (!OPTIMIZE_HPPA)
295 		return bpf_get_reg32(reg, tmp, ctx);
296 
297 	if (is_stacked(hi(reg))) {
298 		reg = tmp;
299 	}
300 	REG_SET_SEEN(ctx, lo(reg));
301 	return reg;
302 }
303 
bpf_put_reg32(const s8 * reg,const s8 * src,struct hppa_jit_context * ctx)304 static void bpf_put_reg32(const s8 *reg, const s8 *src,
305 			  struct hppa_jit_context *ctx)
306 {
307 	if (is_stacked(lo(reg))) {
308 		REG_SET_SEEN(ctx, lo(src));
309 		emit(hppa_stw(lo(src), REG_SIZE * lo(reg), HPPA_REG_SP), ctx);
310 		if (1 && !ctx->prog->aux->verifier_zext) {
311 			REG_SET_SEEN(ctx, hi(reg));
312 			emit(hppa_stw(HPPA_REG_ZERO, REG_SIZE * hi(reg), HPPA_REG_SP), ctx);
313 		}
314 	} else if (1 && !ctx->prog->aux->verifier_zext) {
315 		REG_SET_SEEN(ctx, hi(reg));
316 		emit_hppa_copy(HPPA_REG_ZERO, hi(reg), ctx);
317 	}
318 }
319 
320 /* extern hppa millicode functions */
321 extern void $$mulI(void);
322 extern void $$divU(void);
323 extern void $$remU(void);
324 
emit_call_millicode(void * func,const s8 arg0,const s8 arg1,u8 opcode,struct hppa_jit_context * ctx)325 static void emit_call_millicode(void *func, const s8 arg0,
326 		const s8 arg1, u8 opcode, struct hppa_jit_context *ctx)
327 {
328 	u32 func_addr;
329 
330 	emit_hppa_copy(arg0, HPPA_REG_ARG0, ctx);
331 	emit_hppa_copy(arg1, HPPA_REG_ARG1, ctx);
332 
333 	/* libcgcc overwrites HPPA_REG_RET0/1, save temp. in dest. */
334 	if (arg0 != HPPA_REG_RET1)
335 		bpf_save_R0(ctx);
336 
337 	func_addr = (uintptr_t) dereference_function_descriptor(func);
338 	emit(hppa_ldil(func_addr, HPPA_REG_R31), ctx);
339 	/* skip the following be_l instruction if divisor is zero. */
340 	if (BPF_OP(opcode) == BPF_DIV || BPF_OP(opcode) == BPF_MOD) {
341 		if (BPF_OP(opcode) == BPF_DIV)
342 			emit_hppa_copy(HPPA_REG_ZERO, HPPA_REG_RET1, ctx);
343 		else
344 			emit_hppa_copy(HPPA_REG_ARG0, HPPA_REG_RET1, ctx);
345 		emit(hppa_or_cond(HPPA_REG_ARG1, HPPA_REG_ZERO, 1, 0, HPPA_REG_ZERO), ctx);
346 	}
347 	/* Note: millicode functions use r31 as return pointer instead of rp */
348 	emit(hppa_be_l(im11(func_addr) >> 2, HPPA_REG_R31, NOP_NEXT_INSTR), ctx);
349 	emit(hppa_nop(), ctx); /* this nop is needed here for delay slot */
350 
351 	/* Note: millicode functions return result in RET1, not RET0 */
352 	emit_hppa_copy(HPPA_REG_RET1, arg0, ctx);
353 
354 	/* restore HPPA_REG_RET0/1, temp. save in dest. */
355 	if (arg0 != HPPA_REG_RET1)
356 		bpf_restore_R0(ctx);
357 }
358 
emit_call_libgcc_ll(void * func,const s8 * arg0,const s8 * arg1,u8 opcode,struct hppa_jit_context * ctx)359 static void emit_call_libgcc_ll(void *func, const s8 *arg0,
360 		const s8 *arg1, u8 opcode, struct hppa_jit_context *ctx)
361 {
362 	u32 func_addr;
363 
364 	emit_hppa_copy(lo(arg0), HPPA_REG_ARG0, ctx);
365 	emit_hppa_copy(hi(arg0), HPPA_REG_ARG1, ctx);
366 	emit_hppa_copy(lo(arg1), HPPA_REG_ARG2, ctx);
367 	emit_hppa_copy(hi(arg1), HPPA_REG_ARG3, ctx);
368 
369 	/* libcgcc overwrites HPPA_REG_RET0/_RET1, so keep copy of R0 on stack */
370 	if (hi(arg0) != HPPA_REG_RET0)
371 		bpf_save_R0(ctx);
372 
373 	/* prepare stack */
374 	emit(hppa_ldo(2 * FRAME_SIZE, HPPA_REG_SP, HPPA_REG_SP), ctx);
375 
376 	func_addr = (uintptr_t) dereference_function_descriptor(func);
377 	emit(hppa_ldil(func_addr, HPPA_REG_R31), ctx);
378         /* zero out the following be_l instruction if divisor is 0 (and set default values) */
379 	if (BPF_OP(opcode) == BPF_DIV || BPF_OP(opcode) == BPF_MOD) {
380 		emit_hppa_copy(HPPA_REG_ZERO, HPPA_REG_RET0, ctx);
381 		if (BPF_OP(opcode) == BPF_DIV)
382 			emit_hppa_copy(HPPA_REG_ZERO, HPPA_REG_RET1, ctx);
383 		else
384 			emit_hppa_copy(HPPA_REG_ARG0, HPPA_REG_RET1, ctx);
385 		emit(hppa_or_cond(HPPA_REG_ARG2, HPPA_REG_ARG3, 1, 0, HPPA_REG_ZERO), ctx);
386 	}
387 	emit(hppa_be_l(im11(func_addr) >> 2, HPPA_REG_R31, EXEC_NEXT_INSTR), ctx);
388 	emit_hppa_copy(HPPA_REG_R31, HPPA_REG_RP, ctx);
389 
390 	/* restore stack */
391 	emit(hppa_ldo(-2 * FRAME_SIZE, HPPA_REG_SP, HPPA_REG_SP), ctx);
392 
393 	emit_hppa_copy(HPPA_REG_RET0, hi(arg0), ctx);
394 	emit_hppa_copy(HPPA_REG_RET1, lo(arg0), ctx);
395 
396 	/* restore HPPA_REG_RET0/_RET1 */
397 	if (hi(arg0) != HPPA_REG_RET0)
398 		bpf_restore_R0(ctx);
399 }
400 
emit_jump(s32 paoff,bool force_far,struct hppa_jit_context * ctx)401 static void emit_jump(s32 paoff, bool force_far,
402 			       struct hppa_jit_context *ctx)
403 {
404 	unsigned long pc, addr;
405 
406 	/* Note: allocate 2 instructions for jumps if force_far is set. */
407 	if (relative_bits_ok(paoff - HPPA_BRANCH_DISPLACEMENT, 17)) {
408 		/* use BL,short branch followed by nop() */
409 		emit(hppa_bl(paoff - HPPA_BRANCH_DISPLACEMENT, HPPA_REG_ZERO), ctx);
410 		if (force_far)
411 			emit(hppa_nop(), ctx);
412 		return;
413 	}
414 
415 	pc = (uintptr_t) &ctx->insns[ctx->ninsns];
416 	addr = pc + (paoff * HPPA_INSN_SIZE);
417 	emit(hppa_ldil(addr, HPPA_REG_R31), ctx);
418 	emit(hppa_be_l(im11(addr) >> 2, HPPA_REG_R31, NOP_NEXT_INSTR), ctx); // be,l,n addr(sr4,r31), %sr0, %r31
419 }
420 
emit_alu_i64(const s8 * dst,s32 imm,struct hppa_jit_context * ctx,const u8 op)421 static void emit_alu_i64(const s8 *dst, s32 imm,
422 			 struct hppa_jit_context *ctx, const u8 op)
423 {
424 	const s8 *tmp1 = regmap[TMP_REG_1];
425 	const s8 *rd;
426 
427 	if (0 && op == BPF_MOV)
428 		rd = bpf_get_reg64_ref(dst, tmp1, false, ctx);
429 	else
430 		rd = bpf_get_reg64(dst, tmp1, ctx);
431 
432 	/* dst = dst OP imm */
433 	switch (op) {
434 	case BPF_MOV:
435 		emit_imm32(rd, imm, ctx);
436 		break;
437 	case BPF_AND:
438 		emit_imm(HPPA_REG_T0, imm, ctx);
439 		emit(hppa_and(lo(rd), HPPA_REG_T0, lo(rd)), ctx);
440 		if (imm >= 0)
441 			emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
442 		break;
443 	case BPF_OR:
444 		emit_imm(HPPA_REG_T0, imm, ctx);
445 		emit(hppa_or(lo(rd), HPPA_REG_T0, lo(rd)), ctx);
446 		if (imm < 0)
447 			emit_imm(hi(rd), -1, ctx);
448 		break;
449 	case BPF_XOR:
450 		emit_imm(HPPA_REG_T0, imm, ctx);
451 		emit_hppa_xor(lo(rd), HPPA_REG_T0, lo(rd), ctx);
452 		if (imm < 0) {
453 			emit_imm(HPPA_REG_T0, -1, ctx);
454 			emit_hppa_xor(hi(rd), HPPA_REG_T0, hi(rd), ctx);
455 		}
456 		break;
457 	case BPF_LSH:
458 		if (imm == 0)
459 			break;
460 		if (imm > 32) {
461 			imm -= 32;
462 			emit(hppa_zdep(lo(rd), imm, imm, hi(rd)), ctx);
463 			emit_hppa_copy(HPPA_REG_ZERO, lo(rd), ctx);
464 		} else if (imm == 32) {
465 			emit_hppa_copy(lo(rd), hi(rd), ctx);
466 			emit_hppa_copy(HPPA_REG_ZERO, lo(rd), ctx);
467 		} else {
468 			emit(hppa_shd(hi(rd), lo(rd), 32 - imm, hi(rd)), ctx);
469 			emit(hppa_zdep(lo(rd), imm, imm, lo(rd)), ctx);
470 		}
471 		break;
472 	case BPF_RSH:
473 		if (imm == 0)
474 			break;
475 		if (imm > 32) {
476 			imm -= 32;
477 			emit(hppa_shr(hi(rd), imm, lo(rd)), ctx);
478 			emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
479 		} else if (imm == 32) {
480 			emit_hppa_copy(hi(rd), lo(rd), ctx);
481 			emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
482 		} else {
483 			emit(hppa_shrpw(hi(rd), lo(rd), imm, lo(rd)), ctx);
484 			emit(hppa_shr(hi(rd), imm, hi(rd)), ctx);
485 		}
486 		break;
487 	case BPF_ARSH:
488 		if (imm == 0)
489 			break;
490 		if (imm > 32) {
491 			imm -= 32;
492 			emit(hppa_extrws(hi(rd), 31 - imm, imm, lo(rd)), ctx);
493 			emit(hppa_extrws(hi(rd), 0, 31, hi(rd)), ctx);
494 		} else if (imm == 32) {
495 			emit_hppa_copy(hi(rd), lo(rd), ctx);
496 			emit(hppa_extrws(hi(rd), 0, 31, hi(rd)), ctx);
497 		} else {
498 			emit(hppa_shrpw(hi(rd), lo(rd), imm, lo(rd)), ctx);
499 			emit(hppa_extrws(hi(rd), 31 - imm, imm, hi(rd)), ctx);
500 		}
501 		break;
502 	default:
503 		WARN_ON(1);
504 	}
505 
506 	bpf_put_reg64(dst, rd, ctx);
507 }
508 
emit_alu_i32(const s8 * dst,s32 imm,struct hppa_jit_context * ctx,const u8 op)509 static void emit_alu_i32(const s8 *dst, s32 imm,
510 			 struct hppa_jit_context *ctx, const u8 op)
511 {
512 	const s8 *tmp1 = regmap[TMP_REG_1];
513 	const s8 *rd = bpf_get_reg32(dst, tmp1, ctx);
514 
515 	if (op == BPF_MOV)
516 		rd = bpf_get_reg32_ref(dst, tmp1, ctx);
517 	else
518 		rd = bpf_get_reg32(dst, tmp1, ctx);
519 
520 	/* dst = dst OP imm */
521 	switch (op) {
522 	case BPF_MOV:
523 		emit_imm(lo(rd), imm, ctx);
524 		break;
525 	case BPF_ADD:
526 		emit_imm(HPPA_REG_T0, imm, ctx);
527 		emit(hppa_add(lo(rd), HPPA_REG_T0, lo(rd)), ctx);
528 		break;
529 	case BPF_SUB:
530 		emit_imm(HPPA_REG_T0, imm, ctx);
531 		emit(hppa_sub(lo(rd), HPPA_REG_T0, lo(rd)), ctx);
532 		break;
533 	case BPF_AND:
534 		emit_imm(HPPA_REG_T0, imm, ctx);
535 		emit(hppa_and(lo(rd), HPPA_REG_T0, lo(rd)), ctx);
536 		break;
537 	case BPF_OR:
538 		emit_imm(HPPA_REG_T0, imm, ctx);
539 		emit(hppa_or(lo(rd), HPPA_REG_T0, lo(rd)), ctx);
540 		break;
541 	case BPF_XOR:
542 		emit_imm(HPPA_REG_T0, imm, ctx);
543 		emit_hppa_xor(lo(rd), HPPA_REG_T0, lo(rd), ctx);
544 		break;
545 	case BPF_LSH:
546 		if (imm != 0)
547 			emit(hppa_zdep(lo(rd), imm, imm, lo(rd)), ctx);
548 		break;
549 	case BPF_RSH:
550 		if (imm != 0)
551 			emit(hppa_shr(lo(rd), imm, lo(rd)), ctx);
552 		break;
553 	case BPF_ARSH:
554 		if (imm != 0)
555 			emit(hppa_extrws(lo(rd), 31 - imm, imm, lo(rd)), ctx);
556 		break;
557 	default:
558 		WARN_ON(1);
559 	}
560 
561 	bpf_put_reg32(dst, rd, ctx);
562 }
563 
emit_alu_r64(const s8 * dst,const s8 * src,struct hppa_jit_context * ctx,const u8 op)564 static void emit_alu_r64(const s8 *dst, const s8 *src,
565 			 struct hppa_jit_context *ctx, const u8 op)
566 {
567 	const s8 *tmp1 = regmap[TMP_REG_1];
568 	const s8 *tmp2 = regmap[TMP_REG_2];
569 	const s8 *rd;
570 	const s8 *rs = bpf_get_reg64(src, tmp2, ctx);
571 
572 	if (op == BPF_MOV)
573 		rd = bpf_get_reg64_ref(dst, tmp1, false, ctx);
574 	else
575 		rd = bpf_get_reg64(dst, tmp1, ctx);
576 
577 	/* dst = dst OP src */
578 	switch (op) {
579 	case BPF_MOV:
580 		emit_hppa_copy(lo(rs), lo(rd), ctx);
581 		emit_hppa_copy(hi(rs), hi(rd), ctx);
582 		break;
583 	case BPF_ADD:
584 		emit(hppa_add(lo(rd), lo(rs), lo(rd)), ctx);
585 		emit(hppa_addc(hi(rd), hi(rs), hi(rd)), ctx);
586 		break;
587 	case BPF_SUB:
588 		emit(hppa_sub(lo(rd), lo(rs), lo(rd)), ctx);
589 		emit(hppa_subb(hi(rd), hi(rs), hi(rd)), ctx);
590 		break;
591 	case BPF_AND:
592 		emit(hppa_and(lo(rd), lo(rs), lo(rd)), ctx);
593 		emit(hppa_and(hi(rd), hi(rs), hi(rd)), ctx);
594 		break;
595 	case BPF_OR:
596 		emit(hppa_or(lo(rd), lo(rs), lo(rd)), ctx);
597 		emit(hppa_or(hi(rd), hi(rs), hi(rd)), ctx);
598 		break;
599 	case BPF_XOR:
600 		emit_hppa_xor(lo(rd), lo(rs), lo(rd), ctx);
601 		emit_hppa_xor(hi(rd), hi(rs), hi(rd), ctx);
602 		break;
603 	case BPF_MUL:
604 		emit_call_libgcc_ll(__muldi3, rd, rs, op, ctx);
605 		break;
606 	case BPF_DIV:
607 		emit_call_libgcc_ll(&hppa_div64, rd, rs, op, ctx);
608 		break;
609 	case BPF_MOD:
610 		emit_call_libgcc_ll(&hppa_div64_rem, rd, rs, op, ctx);
611 		break;
612 	case BPF_LSH:
613 		emit_call_libgcc_ll(__ashldi3, rd, rs, op, ctx);
614 		break;
615 	case BPF_RSH:
616 		emit_call_libgcc_ll(__lshrdi3, rd, rs, op, ctx);
617 		break;
618 	case BPF_ARSH:
619 		emit_call_libgcc_ll(__ashrdi3, rd, rs, op, ctx);
620 		break;
621 	case BPF_NEG:
622 		emit(hppa_sub(HPPA_REG_ZERO, lo(rd), lo(rd)), ctx);
623 		emit(hppa_subb(HPPA_REG_ZERO, hi(rd), hi(rd)), ctx);
624 		break;
625 	default:
626 		WARN_ON(1);
627 	}
628 
629 	bpf_put_reg64(dst, rd, ctx);
630 }
631 
emit_alu_r32(const s8 * dst,const s8 * src,struct hppa_jit_context * ctx,const u8 op)632 static void emit_alu_r32(const s8 *dst, const s8 *src,
633 			 struct hppa_jit_context *ctx, const u8 op)
634 {
635 	const s8 *tmp1 = regmap[TMP_REG_1];
636 	const s8 *tmp2 = regmap[TMP_REG_2];
637 	const s8 *rd;
638 	const s8 *rs = bpf_get_reg32(src, tmp2, ctx);
639 
640 	if (op == BPF_MOV)
641 		rd = bpf_get_reg32_ref(dst, tmp1, ctx);
642 	else
643 		rd = bpf_get_reg32(dst, tmp1, ctx);
644 
645 	/* dst = dst OP src */
646 	switch (op) {
647 	case BPF_MOV:
648 		emit_hppa_copy(lo(rs), lo(rd), ctx);
649 		break;
650 	case BPF_ADD:
651 		emit(hppa_add(lo(rd), lo(rs), lo(rd)), ctx);
652 		break;
653 	case BPF_SUB:
654 		emit(hppa_sub(lo(rd), lo(rs), lo(rd)), ctx);
655 		break;
656 	case BPF_AND:
657 		emit(hppa_and(lo(rd), lo(rs), lo(rd)), ctx);
658 		break;
659 	case BPF_OR:
660 		emit(hppa_or(lo(rd), lo(rs), lo(rd)), ctx);
661 		break;
662 	case BPF_XOR:
663 		emit_hppa_xor(lo(rd), lo(rs), lo(rd), ctx);
664 		break;
665 	case BPF_MUL:
666 		emit_call_millicode($$mulI, lo(rd), lo(rs), op, ctx);
667 		break;
668 	case BPF_DIV:
669 		emit_call_millicode($$divU, lo(rd), lo(rs), op, ctx);
670 		break;
671 	case BPF_MOD:
672 		emit_call_millicode($$remU, lo(rd), lo(rs), op, ctx);
673 		break;
674 	case BPF_LSH:
675 		emit(hppa_subi(0x1f, lo(rs), HPPA_REG_T0), ctx);
676 		emit(hppa_mtsar(HPPA_REG_T0), ctx);
677 		emit(hppa_depwz_sar(lo(rd), lo(rd)), ctx);
678 		break;
679 	case BPF_RSH:
680 		emit(hppa_mtsar(lo(rs)), ctx);
681 		emit(hppa_shrpw_sar(lo(rd), lo(rd)), ctx);
682 		break;
683 	case BPF_ARSH: /* sign extending arithmetic shift right */
684 		// emit(hppa_beq(lo(rs), HPPA_REG_ZERO, 2), ctx);
685 		emit(hppa_subi(0x1f, lo(rs), HPPA_REG_T0), ctx);
686 		emit(hppa_mtsar(HPPA_REG_T0), ctx);
687 		emit(hppa_extrws_sar(lo(rd), lo(rd)), ctx);
688 		break;
689 	case BPF_NEG:
690 		emit(hppa_sub(HPPA_REG_ZERO, lo(rd), lo(rd)), ctx);  // sub r0,rd,rd
691 		break;
692 	default:
693 		WARN_ON(1);
694 	}
695 
696 	bpf_put_reg32(dst, rd, ctx);
697 }
698 
emit_branch_r64(const s8 * src1,const s8 * src2,s32 paoff,struct hppa_jit_context * ctx,const u8 op)699 static int emit_branch_r64(const s8 *src1, const s8 *src2, s32 paoff,
700 			   struct hppa_jit_context *ctx, const u8 op)
701 {
702 	int e, s = ctx->ninsns;
703 	const s8 *tmp1 = regmap[TMP_REG_1];
704 	const s8 *tmp2 = regmap[TMP_REG_2];
705 
706 	const s8 *rs1 = bpf_get_reg64(src1, tmp1, ctx);
707 	const s8 *rs2 = bpf_get_reg64(src2, tmp2, ctx);
708 
709 	/*
710 	 * NO_JUMP skips over the rest of the instructions and the
711 	 * emit_jump, meaning the BPF branch is not taken.
712 	 * JUMP skips directly to the emit_jump, meaning
713 	 * the BPF branch is taken.
714 	 *
715 	 * The fallthrough case results in the BPF branch being taken.
716 	 */
717 #define NO_JUMP(idx)	(2 + (idx) - 1)
718 #define JUMP(idx)	(0 + (idx) - 1)
719 
720 	switch (op) {
721 	case BPF_JEQ:
722 		emit(hppa_bne(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
723 		emit(hppa_bne(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
724 		break;
725 	case BPF_JGT:
726 		emit(hppa_bgtu(hi(rs1), hi(rs2), JUMP(2)), ctx);
727 		emit(hppa_bltu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
728 		emit(hppa_bleu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
729 		break;
730 	case BPF_JLT:
731 		emit(hppa_bltu(hi(rs1), hi(rs2), JUMP(2)), ctx);
732 		emit(hppa_bgtu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
733 		emit(hppa_bgeu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
734 		break;
735 	case BPF_JGE:
736 		emit(hppa_bgtu(hi(rs1), hi(rs2), JUMP(2)), ctx);
737 		emit(hppa_bltu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
738 		emit(hppa_bltu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
739 		break;
740 	case BPF_JLE:
741 		emit(hppa_bltu(hi(rs1), hi(rs2), JUMP(2)), ctx);
742 		emit(hppa_bgtu(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
743 		emit(hppa_bgtu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
744 		break;
745 	case BPF_JNE:
746 		emit(hppa_bne(hi(rs1), hi(rs2), JUMP(1)), ctx);
747 		emit(hppa_beq(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
748 		break;
749 	case BPF_JSGT:
750 		emit(hppa_bgt(hi(rs1), hi(rs2), JUMP(2)), ctx);
751 		emit(hppa_blt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
752 		emit(hppa_bleu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
753 		break;
754 	case BPF_JSLT:
755 		emit(hppa_blt(hi(rs1), hi(rs2), JUMP(2)), ctx);
756 		emit(hppa_bgt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
757 		emit(hppa_bgeu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
758 		break;
759 	case BPF_JSGE:
760 		emit(hppa_bgt(hi(rs1), hi(rs2), JUMP(2)), ctx);
761 		emit(hppa_blt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
762 		emit(hppa_bltu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
763 		break;
764 	case BPF_JSLE:
765 		emit(hppa_blt(hi(rs1), hi(rs2), JUMP(2)), ctx);
766 		emit(hppa_bgt(hi(rs1), hi(rs2), NO_JUMP(1)), ctx);
767 		emit(hppa_bgtu(lo(rs1), lo(rs2), NO_JUMP(0)), ctx);
768 		break;
769 	case BPF_JSET:
770 		emit(hppa_and(hi(rs1), hi(rs2), HPPA_REG_T0), ctx);
771 		emit(hppa_and(lo(rs1), lo(rs2), HPPA_REG_T1), ctx);
772 		emit(hppa_bne(HPPA_REG_T0, HPPA_REG_ZERO, JUMP(1)), ctx);
773 		emit(hppa_beq(HPPA_REG_T1, HPPA_REG_ZERO, NO_JUMP(0)), ctx);
774 		break;
775 	default:
776 		WARN_ON(1);
777 	}
778 
779 #undef NO_JUMP
780 #undef JUMP
781 
782 	e = ctx->ninsns;
783 	/* Adjust for extra insns. */
784 	paoff -= (e - s);
785 	emit_jump(paoff, true, ctx);
786 	return 0;
787 }
788 
emit_bcc(u8 op,u8 rd,u8 rs,int paoff,struct hppa_jit_context * ctx)789 static int emit_bcc(u8 op, u8 rd, u8 rs, int paoff, struct hppa_jit_context *ctx)
790 {
791 	int e, s;
792 	bool far = false;
793 	int off;
794 
795 	if (op == BPF_JSET) {
796 		/*
797 		 * BPF_JSET is a special case: it has no inverse so we always
798 		 * treat it as a far branch.
799 		 */
800 		emit(hppa_and(rd, rs, HPPA_REG_T0), ctx);
801 		paoff -= 1; /* reduce offset due to hppa_and() above */
802 		rd = HPPA_REG_T0;
803 		rs = HPPA_REG_ZERO;
804 		op = BPF_JNE;
805 	}
806 
807 	s = ctx->ninsns;
808 
809 	if (!relative_bits_ok(paoff - HPPA_BRANCH_DISPLACEMENT, 12)) {
810 		op = invert_bpf_cond(op);
811 		far = true;
812 	}
813 
814 	/*
815 	 * For a far branch, the condition is negated and we jump over the
816 	 * branch itself, and the three instructions from emit_jump.
817 	 * For a near branch, just use paoff.
818 	 */
819 	off = far ? (HPPA_BRANCH_DISPLACEMENT - 1) : paoff - HPPA_BRANCH_DISPLACEMENT;
820 
821 	switch (op) {
822 	/* IF (dst COND src) JUMP off */
823 	case BPF_JEQ:
824 		emit(hppa_beq(rd, rs, off), ctx);
825 		break;
826 	case BPF_JGT:
827 		emit(hppa_bgtu(rd, rs, off), ctx);
828 		break;
829 	case BPF_JLT:
830 		emit(hppa_bltu(rd, rs, off), ctx);
831 		break;
832 	case BPF_JGE:
833 		emit(hppa_bgeu(rd, rs, off), ctx);
834 		break;
835 	case BPF_JLE:
836 		emit(hppa_bleu(rd, rs, off), ctx);
837 		break;
838 	case BPF_JNE:
839 		emit(hppa_bne(rd, rs, off), ctx);
840 		break;
841 	case BPF_JSGT:
842 		emit(hppa_bgt(rd, rs, off), ctx);
843 		break;
844 	case BPF_JSLT:
845 		emit(hppa_blt(rd, rs, off), ctx);
846 		break;
847 	case BPF_JSGE:
848 		emit(hppa_bge(rd, rs, off), ctx);
849 		break;
850 	case BPF_JSLE:
851 		emit(hppa_ble(rd, rs, off), ctx);
852 		break;
853 	default:
854 		WARN_ON(1);
855 	}
856 
857 	if (far) {
858 		e = ctx->ninsns;
859 		/* Adjust for extra insns. */
860 		paoff -= (e - s);
861 		emit_jump(paoff, true, ctx);
862 	}
863 	return 0;
864 }
865 
emit_branch_r32(const s8 * src1,const s8 * src2,s32 paoff,struct hppa_jit_context * ctx,const u8 op)866 static int emit_branch_r32(const s8 *src1, const s8 *src2, s32 paoff,
867 			   struct hppa_jit_context *ctx, const u8 op)
868 {
869 	int e, s = ctx->ninsns;
870 	const s8 *tmp1 = regmap[TMP_REG_1];
871 	const s8 *tmp2 = regmap[TMP_REG_2];
872 
873 	const s8 *rs1 = bpf_get_reg32(src1, tmp1, ctx);
874 	const s8 *rs2 = bpf_get_reg32(src2, tmp2, ctx);
875 
876 	e = ctx->ninsns;
877 	/* Adjust for extra insns. */
878 	paoff -= (e - s);
879 
880 	if (emit_bcc(op, lo(rs1), lo(rs2), paoff, ctx))
881 		return -1;
882 
883 	return 0;
884 }
885 
emit_call(bool fixed,u64 addr,struct hppa_jit_context * ctx)886 static void emit_call(bool fixed, u64 addr, struct hppa_jit_context *ctx)
887 {
888 	const s8 *tmp = regmap[TMP_REG_1];
889 	const s8 *r0 = regmap[BPF_REG_0];
890 	const s8 *reg;
891 	const int offset_sp = 2 * STACK_ALIGN;
892 
893 	/* prepare stack */
894 	emit(hppa_ldo(offset_sp, HPPA_REG_SP, HPPA_REG_SP), ctx);
895 
896 	/* load R1 & R2 in registers, R3-R5 to stack. */
897 	reg = bpf_get_reg64_offset(regmap[BPF_REG_5], tmp, offset_sp, ctx);
898 	emit(hppa_stw(hi(reg), -0x48, HPPA_REG_SP), ctx);
899 	emit(hppa_stw(lo(reg), -0x44, HPPA_REG_SP), ctx);
900 
901 	reg = bpf_get_reg64_offset(regmap[BPF_REG_4], tmp, offset_sp, ctx);
902 	emit(hppa_stw(hi(reg), -0x40, HPPA_REG_SP), ctx);
903 	emit(hppa_stw(lo(reg), -0x3c, HPPA_REG_SP), ctx);
904 
905 	reg = bpf_get_reg64_offset(regmap[BPF_REG_3], tmp, offset_sp, ctx);
906 	emit(hppa_stw(hi(reg), -0x38, HPPA_REG_SP), ctx);
907 	emit(hppa_stw(lo(reg), -0x34, HPPA_REG_SP), ctx);
908 
909 	reg = bpf_get_reg64_offset(regmap[BPF_REG_2], tmp, offset_sp, ctx);
910 	emit_hppa_copy(hi(reg), HPPA_REG_ARG3, ctx);
911 	emit_hppa_copy(lo(reg), HPPA_REG_ARG2, ctx);
912 
913 	reg = bpf_get_reg64_offset(regmap[BPF_REG_1], tmp, offset_sp, ctx);
914 	emit_hppa_copy(hi(reg), HPPA_REG_ARG1, ctx);
915 	emit_hppa_copy(lo(reg), HPPA_REG_ARG0, ctx);
916 
917 	/* backup TCC */
918 	if (REG_WAS_SEEN(ctx, HPPA_REG_TCC))
919 		emit(hppa_copy(HPPA_REG_TCC, HPPA_REG_TCC_SAVED), ctx);
920 
921 	/*
922 	 * Use ldil() to load absolute address. Don't use emit_imm as the
923 	 * number of emitted instructions should not depend on the value of
924 	 * addr.
925 	 */
926 	emit(hppa_ldil(addr, HPPA_REG_R31), ctx);
927 	emit(hppa_be_l(im11(addr) >> 2, HPPA_REG_R31, EXEC_NEXT_INSTR), ctx);
928 	/* set return address in delay slot */
929 	emit_hppa_copy(HPPA_REG_R31, HPPA_REG_RP, ctx);
930 
931 	/* restore TCC */
932 	if (REG_WAS_SEEN(ctx, HPPA_REG_TCC))
933 		emit(hppa_copy(HPPA_REG_TCC_SAVED, HPPA_REG_TCC), ctx);
934 
935 	/* restore stack */
936 	emit(hppa_ldo(-offset_sp, HPPA_REG_SP, HPPA_REG_SP), ctx);
937 
938 	/* set return value. */
939 	emit_hppa_copy(HPPA_REG_RET0, hi(r0), ctx);
940 	emit_hppa_copy(HPPA_REG_RET1, lo(r0), ctx);
941 }
942 
emit_bpf_tail_call(int insn,struct hppa_jit_context * ctx)943 static int emit_bpf_tail_call(int insn, struct hppa_jit_context *ctx)
944 {
945 	/*
946 	 * R1 -> &ctx
947 	 * R2 -> &array
948 	 * R3 -> index
949 	 */
950 	int off;
951 	const s8 *arr_reg = regmap[BPF_REG_2];
952 	const s8 *idx_reg = regmap[BPF_REG_3];
953 	struct bpf_array bpfa;
954 	struct bpf_prog bpfp;
955 
956 	/* get address of TCC main exit function for error case into rp */
957 	emit(EXIT_PTR_LOAD(HPPA_REG_RP), ctx);
958 
959 	/* max_entries = array->map.max_entries; */
960 	off = offsetof(struct bpf_array, map.max_entries);
961 	BUILD_BUG_ON(sizeof(bpfa.map.max_entries) != 4);
962 	emit(hppa_ldw(off, lo(arr_reg), HPPA_REG_T1), ctx);
963 
964 	/*
965 	 * if (index >= max_entries)
966 	 *   goto out;
967 	 */
968 	emit(hppa_bltu(lo(idx_reg), HPPA_REG_T1, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
969 	emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
970 
971 	/*
972 	 * if (--tcc < 0)
973 	 *   goto out;
974 	 */
975 	REG_FORCE_SEEN(ctx, HPPA_REG_TCC);
976 	emit(hppa_ldo(-1, HPPA_REG_TCC, HPPA_REG_TCC), ctx);
977 	emit(hppa_bge(HPPA_REG_TCC, HPPA_REG_ZERO, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
978 	emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
979 
980 	/*
981 	 * prog = array->ptrs[index];
982 	 * if (!prog)
983 	 *   goto out;
984 	 */
985 	BUILD_BUG_ON(sizeof(bpfa.ptrs[0]) != 4);
986 	emit(hppa_sh2add(lo(idx_reg), lo(arr_reg), HPPA_REG_T0), ctx);
987 	off = offsetof(struct bpf_array, ptrs);
988 	BUILD_BUG_ON(!relative_bits_ok(off, 11));
989 	emit(hppa_ldw(off, HPPA_REG_T0, HPPA_REG_T0), ctx);
990 	emit(hppa_bne(HPPA_REG_T0, HPPA_REG_ZERO, 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
991 	emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
992 
993 	/*
994 	 * tcc = temp_tcc;
995 	 * goto *(prog->bpf_func + 4);
996 	 */
997 	off = offsetof(struct bpf_prog, bpf_func);
998 	BUILD_BUG_ON(!relative_bits_ok(off, 11));
999 	BUILD_BUG_ON(sizeof(bpfp.bpf_func) != 4);
1000 	emit(hppa_ldw(off, HPPA_REG_T0, HPPA_REG_T0), ctx);
1001 	/* Epilogue jumps to *(t0 + 4). */
1002 	__build_epilogue(true, ctx);
1003 	return 0;
1004 }
1005 
emit_load_r64(const s8 * dst,const s8 * src,s16 off,struct hppa_jit_context * ctx,const u8 size)1006 static int emit_load_r64(const s8 *dst, const s8 *src, s16 off,
1007 			 struct hppa_jit_context *ctx, const u8 size)
1008 {
1009 	const s8 *tmp1 = regmap[TMP_REG_1];
1010 	const s8 *tmp2 = regmap[TMP_REG_2];
1011 	const s8 *rd = bpf_get_reg64_ref(dst, tmp1, ctx->prog->aux->verifier_zext, ctx);
1012 	const s8 *rs = bpf_get_reg64(src, tmp2, ctx);
1013 	s8 srcreg;
1014 
1015 	/* need to calculate address since offset does not fit in 14 bits? */
1016 	if (relative_bits_ok(off, 14))
1017 		srcreg = lo(rs);
1018 	else {
1019 		/* need to use R1 here, since addil puts result into R1 */
1020 		srcreg = HPPA_REG_R1;
1021 		emit(hppa_addil(off, lo(rs)), ctx);
1022 		off = im11(off);
1023 	}
1024 
1025 	/* LDX: dst = *(size *)(src + off) */
1026 	switch (size) {
1027 	case BPF_B:
1028 		emit(hppa_ldb(off + 0, srcreg, lo(rd)), ctx);
1029 		if (!ctx->prog->aux->verifier_zext)
1030 			emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1031 		break;
1032 	case BPF_H:
1033 		emit(hppa_ldh(off + 0, srcreg, lo(rd)), ctx);
1034 		if (!ctx->prog->aux->verifier_zext)
1035 			emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1036 		break;
1037 	case BPF_W:
1038 		emit(hppa_ldw(off + 0, srcreg, lo(rd)), ctx);
1039 		if (!ctx->prog->aux->verifier_zext)
1040 			emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1041 		break;
1042 	case BPF_DW:
1043 		emit(hppa_ldw(off + 0, srcreg, hi(rd)), ctx);
1044 		emit(hppa_ldw(off + 4, srcreg, lo(rd)), ctx);
1045 		break;
1046 	}
1047 
1048 	bpf_put_reg64(dst, rd, ctx);
1049 	return 0;
1050 }
1051 
emit_store_r64(const s8 * dst,const s8 * src,s16 off,struct hppa_jit_context * ctx,const u8 size,const u8 mode)1052 static int emit_store_r64(const s8 *dst, const s8 *src, s16 off,
1053 			  struct hppa_jit_context *ctx, const u8 size,
1054 			  const u8 mode)
1055 {
1056 	const s8 *tmp1 = regmap[TMP_REG_1];
1057 	const s8 *tmp2 = regmap[TMP_REG_2];
1058 	const s8 *rd = bpf_get_reg64(dst, tmp1, ctx);
1059 	const s8 *rs = bpf_get_reg64(src, tmp2, ctx);
1060 	s8 dstreg;
1061 
1062 	/* need to calculate address since offset does not fit in 14 bits? */
1063 	if (relative_bits_ok(off, 14))
1064 		dstreg = lo(rd);
1065 	else {
1066 		/* need to use R1 here, since addil puts result into R1 */
1067 		dstreg = HPPA_REG_R1;
1068 		emit(hppa_addil(off, lo(rd)), ctx);
1069 		off = im11(off);
1070 	}
1071 
1072 	/* ST: *(size *)(dst + off) = imm */
1073 	switch (size) {
1074 	case BPF_B:
1075 		emit(hppa_stb(lo(rs), off + 0, dstreg), ctx);
1076 		break;
1077 	case BPF_H:
1078 		emit(hppa_sth(lo(rs), off + 0, dstreg), ctx);
1079 		break;
1080 	case BPF_W:
1081 		emit(hppa_stw(lo(rs), off + 0, dstreg), ctx);
1082 		break;
1083 	case BPF_DW:
1084 		emit(hppa_stw(hi(rs), off + 0, dstreg), ctx);
1085 		emit(hppa_stw(lo(rs), off + 4, dstreg), ctx);
1086 		break;
1087 	}
1088 
1089 	return 0;
1090 }
1091 
emit_rev16(const s8 rd,struct hppa_jit_context * ctx)1092 static void emit_rev16(const s8 rd, struct hppa_jit_context *ctx)
1093 {
1094 	emit(hppa_extru(rd, 23, 8, HPPA_REG_T1), ctx);
1095 	emit(hppa_depwz(rd, 23, 8, HPPA_REG_T1), ctx);
1096 	emit(hppa_extru(HPPA_REG_T1, 31, 16, rd), ctx);
1097 }
1098 
emit_rev32(const s8 rs,const s8 rd,struct hppa_jit_context * ctx)1099 static void emit_rev32(const s8 rs, const s8 rd, struct hppa_jit_context *ctx)
1100 {
1101 	emit(hppa_shrpw(rs, rs, 16, HPPA_REG_T1), ctx);
1102 	emit(hppa_depwz(HPPA_REG_T1, 15, 8, HPPA_REG_T1), ctx);
1103 	emit(hppa_shrpw(rs, HPPA_REG_T1, 8, rd), ctx);
1104 }
1105 
emit_zext64(const s8 * dst,struct hppa_jit_context * ctx)1106 static void emit_zext64(const s8 *dst, struct hppa_jit_context *ctx)
1107 {
1108 	const s8 *rd;
1109 	const s8 *tmp1 = regmap[TMP_REG_1];
1110 
1111 	rd = bpf_get_reg64(dst, tmp1, ctx);
1112 	emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1113 	bpf_put_reg64(dst, rd, ctx);
1114 }
1115 
bpf_jit_emit_insn(const struct bpf_insn * insn,struct hppa_jit_context * ctx,bool extra_pass)1116 int bpf_jit_emit_insn(const struct bpf_insn *insn, struct hppa_jit_context *ctx,
1117 		      bool extra_pass)
1118 {
1119 	bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 ||
1120 		BPF_CLASS(insn->code) == BPF_JMP;
1121 	int s, e, paoff, i = insn - ctx->prog->insnsi;
1122 	u8 code = insn->code;
1123 	s16 off = insn->off;
1124 	s32 imm = insn->imm;
1125 
1126 	const s8 *dst = regmap[insn->dst_reg];
1127 	const s8 *src = regmap[insn->src_reg];
1128 	const s8 *tmp1 = regmap[TMP_REG_1];
1129 	const s8 *tmp2 = regmap[TMP_REG_2];
1130 
1131 	if (0) printk("CLASS %03d  CODE %#02x ALU64:%d BPF_SIZE %#02x  "
1132 		"BPF_CODE %#02x  src_reg %d  dst_reg %d\n",
1133 		BPF_CLASS(code), code, (code & BPF_ALU64) ? 1:0, BPF_SIZE(code),
1134 		BPF_OP(code), insn->src_reg, insn->dst_reg);
1135 
1136 	switch (code) {
1137 	/* dst = src */
1138 	case BPF_ALU64 | BPF_MOV | BPF_X:
1139 
1140 	case BPF_ALU64 | BPF_ADD | BPF_X:
1141 	case BPF_ALU64 | BPF_ADD | BPF_K:
1142 
1143 	case BPF_ALU64 | BPF_SUB | BPF_X:
1144 	case BPF_ALU64 | BPF_SUB | BPF_K:
1145 
1146 	case BPF_ALU64 | BPF_AND | BPF_X:
1147 	case BPF_ALU64 | BPF_OR | BPF_X:
1148 	case BPF_ALU64 | BPF_XOR | BPF_X:
1149 
1150 	case BPF_ALU64 | BPF_MUL | BPF_X:
1151 	case BPF_ALU64 | BPF_MUL | BPF_K:
1152 
1153 	case BPF_ALU64 | BPF_DIV | BPF_X:
1154 	case BPF_ALU64 | BPF_DIV | BPF_K:
1155 
1156 	case BPF_ALU64 | BPF_MOD | BPF_X:
1157 	case BPF_ALU64 | BPF_MOD | BPF_K:
1158 
1159 	case BPF_ALU64 | BPF_LSH | BPF_X:
1160 	case BPF_ALU64 | BPF_RSH | BPF_X:
1161 	case BPF_ALU64 | BPF_ARSH | BPF_X:
1162 		if (BPF_SRC(code) == BPF_K) {
1163 			emit_imm32(tmp2, imm, ctx);
1164 			src = tmp2;
1165 		}
1166 		emit_alu_r64(dst, src, ctx, BPF_OP(code));
1167 		break;
1168 
1169 	/* dst = -dst */
1170 	case BPF_ALU64 | BPF_NEG:
1171 		emit_alu_r64(dst, tmp2, ctx, BPF_OP(code));
1172 		break;
1173 
1174 	case BPF_ALU64 | BPF_MOV | BPF_K:
1175 	case BPF_ALU64 | BPF_AND | BPF_K:
1176 	case BPF_ALU64 | BPF_OR | BPF_K:
1177 	case BPF_ALU64 | BPF_XOR | BPF_K:
1178 	case BPF_ALU64 | BPF_LSH | BPF_K:
1179 	case BPF_ALU64 | BPF_RSH | BPF_K:
1180 	case BPF_ALU64 | BPF_ARSH | BPF_K:
1181 		emit_alu_i64(dst, imm, ctx, BPF_OP(code));
1182 		break;
1183 
1184 	case BPF_ALU | BPF_MOV | BPF_X:
1185 		if (imm == 1) {
1186 			/* Special mov32 for zext. */
1187 			emit_zext64(dst, ctx);
1188 			break;
1189 		}
1190 		fallthrough;
1191 	/* dst = dst OP src */
1192 	case BPF_ALU | BPF_ADD | BPF_X:
1193 	case BPF_ALU | BPF_SUB | BPF_X:
1194 	case BPF_ALU | BPF_AND | BPF_X:
1195 	case BPF_ALU | BPF_OR | BPF_X:
1196 	case BPF_ALU | BPF_XOR | BPF_X:
1197 
1198 	case BPF_ALU | BPF_MUL | BPF_X:
1199 	case BPF_ALU | BPF_MUL | BPF_K:
1200 
1201 	case BPF_ALU | BPF_DIV | BPF_X:
1202 	case BPF_ALU | BPF_DIV | BPF_K:
1203 
1204 	case BPF_ALU | BPF_MOD | BPF_X:
1205 	case BPF_ALU | BPF_MOD | BPF_K:
1206 
1207 	case BPF_ALU | BPF_LSH | BPF_X:
1208 	case BPF_ALU | BPF_RSH | BPF_X:
1209 	case BPF_ALU | BPF_ARSH | BPF_X:
1210 		if (BPF_SRC(code) == BPF_K) {
1211 			emit_imm32(tmp2, imm, ctx);
1212 			src = tmp2;
1213 		}
1214 		emit_alu_r32(dst, src, ctx, BPF_OP(code));
1215 		break;
1216 
1217 	/* dst = dst OP imm */
1218 	case BPF_ALU | BPF_MOV | BPF_K:
1219 	case BPF_ALU | BPF_ADD | BPF_K:
1220 	case BPF_ALU | BPF_SUB | BPF_K:
1221 	case BPF_ALU | BPF_AND | BPF_K:
1222 	case BPF_ALU | BPF_OR | BPF_K:
1223 	case BPF_ALU | BPF_XOR | BPF_K:
1224 	case BPF_ALU | BPF_LSH | BPF_K:
1225 	case BPF_ALU | BPF_RSH | BPF_K:
1226 	case BPF_ALU | BPF_ARSH | BPF_K:
1227 		/*
1228 		 * mul,div,mod are handled in the BPF_X case.
1229 		 */
1230 		emit_alu_i32(dst, imm, ctx, BPF_OP(code));
1231 		break;
1232 
1233 	/* dst = -dst */
1234 	case BPF_ALU | BPF_NEG:
1235 		/*
1236 		 * src is ignored---choose tmp2 as a dummy register since it
1237 		 * is not on the stack.
1238 		 */
1239 		emit_alu_r32(dst, tmp2, ctx, BPF_OP(code));
1240 		break;
1241 
1242 	/* dst = BSWAP##imm(dst) */
1243 	case BPF_ALU | BPF_END | BPF_FROM_BE:
1244 	{
1245 		const s8 *rd = bpf_get_reg64(dst, tmp1, ctx);
1246 
1247 		switch (imm) {
1248 		case 16:
1249 			/* zero-extend 16 bits into 64 bits */
1250 			emit(hppa_extru(lo(rd), 31, 16, lo(rd)), ctx);
1251 			fallthrough;
1252 		case 32:
1253 			/* zero-extend 32 bits into 64 bits */
1254 			if (!ctx->prog->aux->verifier_zext)
1255 				emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1256 			break;
1257 		case 64:
1258 			/* Do nothing. */
1259 			break;
1260 		default:
1261 			pr_err("bpf-jit: BPF_END imm %d invalid\n", imm);
1262 			return -1;
1263 		}
1264 
1265 		bpf_put_reg64(dst, rd, ctx);
1266 		break;
1267 	}
1268 
1269 	case BPF_ALU | BPF_END | BPF_FROM_LE:
1270 	{
1271 		const s8 *rd = bpf_get_reg64(dst, tmp1, ctx);
1272 
1273 		switch (imm) {
1274 		case 16:
1275 			emit_rev16(lo(rd), ctx);
1276 			if (!ctx->prog->aux->verifier_zext)
1277 				emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1278 			break;
1279 		case 32:
1280 			emit_rev32(lo(rd), lo(rd), ctx);
1281 			if (!ctx->prog->aux->verifier_zext)
1282 				emit_hppa_copy(HPPA_REG_ZERO, hi(rd), ctx);
1283 			break;
1284 		case 64:
1285 			/* Swap upper and lower halves, then each half. */
1286 			emit_hppa_copy(hi(rd), HPPA_REG_T0, ctx);
1287 			emit_rev32(lo(rd), hi(rd), ctx);
1288 			emit_rev32(HPPA_REG_T0, lo(rd), ctx);
1289 			break;
1290 		default:
1291 			pr_err("bpf-jit: BPF_END imm %d invalid\n", imm);
1292 			return -1;
1293 		}
1294 
1295 		bpf_put_reg64(dst, rd, ctx);
1296 		break;
1297 	}
1298 	/* JUMP off */
1299 	case BPF_JMP | BPF_JA:
1300 		paoff = hppa_offset(i, off, ctx);
1301 		emit_jump(paoff, false, ctx);
1302 		break;
1303 	/* function call */
1304 	case BPF_JMP | BPF_CALL:
1305 	{
1306 		bool fixed;
1307 		int ret;
1308 		u64 addr;
1309 
1310 		ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &addr,
1311 					    &fixed);
1312 		if (ret < 0)
1313 			return ret;
1314 		emit_call(fixed, addr, ctx);
1315 		break;
1316 	}
1317 	/* tail call */
1318 	case BPF_JMP | BPF_TAIL_CALL:
1319 		REG_SET_SEEN_ALL(ctx);
1320 		if (emit_bpf_tail_call(i, ctx))
1321 			return -1;
1322 		break;
1323 	/* IF (dst COND imm) JUMP off */
1324 	case BPF_JMP | BPF_JEQ | BPF_X:
1325 	case BPF_JMP | BPF_JEQ | BPF_K:
1326 	case BPF_JMP32 | BPF_JEQ | BPF_X:
1327 	case BPF_JMP32 | BPF_JEQ | BPF_K:
1328 
1329 	case BPF_JMP | BPF_JNE | BPF_X:
1330 	case BPF_JMP | BPF_JNE | BPF_K:
1331 	case BPF_JMP32 | BPF_JNE | BPF_X:
1332 	case BPF_JMP32 | BPF_JNE | BPF_K:
1333 
1334 	case BPF_JMP | BPF_JLE | BPF_X:
1335 	case BPF_JMP | BPF_JLE | BPF_K:
1336 	case BPF_JMP32 | BPF_JLE | BPF_X:
1337 	case BPF_JMP32 | BPF_JLE | BPF_K:
1338 
1339 	case BPF_JMP | BPF_JLT | BPF_X:
1340 	case BPF_JMP | BPF_JLT | BPF_K:
1341 	case BPF_JMP32 | BPF_JLT | BPF_X:
1342 	case BPF_JMP32 | BPF_JLT | BPF_K:
1343 
1344 	case BPF_JMP | BPF_JGE | BPF_X:
1345 	case BPF_JMP | BPF_JGE | BPF_K:
1346 	case BPF_JMP32 | BPF_JGE | BPF_X:
1347 	case BPF_JMP32 | BPF_JGE | BPF_K:
1348 
1349 	case BPF_JMP | BPF_JGT | BPF_X:
1350 	case BPF_JMP | BPF_JGT | BPF_K:
1351 	case BPF_JMP32 | BPF_JGT | BPF_X:
1352 	case BPF_JMP32 | BPF_JGT | BPF_K:
1353 
1354 	case BPF_JMP | BPF_JSLE | BPF_X:
1355 	case BPF_JMP | BPF_JSLE | BPF_K:
1356 	case BPF_JMP32 | BPF_JSLE | BPF_X:
1357 	case BPF_JMP32 | BPF_JSLE | BPF_K:
1358 
1359 	case BPF_JMP | BPF_JSLT | BPF_X:
1360 	case BPF_JMP | BPF_JSLT | BPF_K:
1361 	case BPF_JMP32 | BPF_JSLT | BPF_X:
1362 	case BPF_JMP32 | BPF_JSLT | BPF_K:
1363 
1364 	case BPF_JMP | BPF_JSGE | BPF_X:
1365 	case BPF_JMP | BPF_JSGE | BPF_K:
1366 	case BPF_JMP32 | BPF_JSGE | BPF_X:
1367 	case BPF_JMP32 | BPF_JSGE | BPF_K:
1368 
1369 	case BPF_JMP | BPF_JSGT | BPF_X:
1370 	case BPF_JMP | BPF_JSGT | BPF_K:
1371 	case BPF_JMP32 | BPF_JSGT | BPF_X:
1372 	case BPF_JMP32 | BPF_JSGT | BPF_K:
1373 
1374 	case BPF_JMP | BPF_JSET | BPF_X:
1375 	case BPF_JMP | BPF_JSET | BPF_K:
1376 	case BPF_JMP32 | BPF_JSET | BPF_X:
1377 	case BPF_JMP32 | BPF_JSET | BPF_K:
1378 		paoff = hppa_offset(i, off, ctx);
1379 		if (BPF_SRC(code) == BPF_K) {
1380 			s = ctx->ninsns;
1381 			emit_imm32(tmp2, imm, ctx);
1382 			src = tmp2;
1383 			e = ctx->ninsns;
1384 			paoff -= (e - s);
1385 		}
1386 		if (is64)
1387 			emit_branch_r64(dst, src, paoff, ctx, BPF_OP(code));
1388 		else
1389 			emit_branch_r32(dst, src, paoff, ctx, BPF_OP(code));
1390 		break;
1391 	/* function return */
1392 	case BPF_JMP | BPF_EXIT:
1393 		if (i == ctx->prog->len - 1)
1394 			break;
1395 		/* load epilogue function pointer and jump to it. */
1396 		emit(EXIT_PTR_LOAD(HPPA_REG_RP), ctx);
1397 		emit(EXIT_PTR_JUMP(HPPA_REG_RP, NOP_NEXT_INSTR), ctx);
1398 		break;
1399 
1400 	/* dst = imm64 */
1401 	case BPF_LD | BPF_IMM | BPF_DW:
1402 	{
1403 		struct bpf_insn insn1 = insn[1];
1404 		u32 upper = insn1.imm;
1405 		u32 lower = imm;
1406 		const s8 *rd = bpf_get_reg64_ref(dst, tmp1, false, ctx);
1407 
1408 		if (0 && bpf_pseudo_func(insn)) {
1409 			WARN_ON(upper); /* we are 32-bit! */
1410 			upper = 0;
1411 			lower = (uintptr_t) dereference_function_descriptor(lower);
1412 		}
1413 
1414 		emit_imm64(rd, upper, lower, ctx);
1415 		bpf_put_reg64(dst, rd, ctx);
1416 		return 1;
1417 	}
1418 
1419 	/* LDX: dst = *(size *)(src + off) */
1420 	case BPF_LDX | BPF_MEM | BPF_B:
1421 	case BPF_LDX | BPF_MEM | BPF_H:
1422 	case BPF_LDX | BPF_MEM | BPF_W:
1423 	case BPF_LDX | BPF_MEM | BPF_DW:
1424 		if (emit_load_r64(dst, src, off, ctx, BPF_SIZE(code)))
1425 			return -1;
1426 		break;
1427 
1428 	/* speculation barrier */
1429 	case BPF_ST | BPF_NOSPEC:
1430 		break;
1431 
1432 	/* ST: *(size *)(dst + off) = imm */
1433 	case BPF_ST | BPF_MEM | BPF_B:
1434 	case BPF_ST | BPF_MEM | BPF_H:
1435 	case BPF_ST | BPF_MEM | BPF_W:
1436 	case BPF_ST | BPF_MEM | BPF_DW:
1437 
1438 	case BPF_STX | BPF_MEM | BPF_B:
1439 	case BPF_STX | BPF_MEM | BPF_H:
1440 	case BPF_STX | BPF_MEM | BPF_W:
1441 	case BPF_STX | BPF_MEM | BPF_DW:
1442 		if (BPF_CLASS(code) == BPF_ST) {
1443 			emit_imm32(tmp2, imm, ctx);
1444 			src = tmp2;
1445 		}
1446 
1447 		if (emit_store_r64(dst, src, off, ctx, BPF_SIZE(code),
1448 				   BPF_MODE(code)))
1449 			return -1;
1450 		break;
1451 
1452 	case BPF_STX | BPF_ATOMIC | BPF_W:
1453 	case BPF_STX | BPF_ATOMIC | BPF_DW:
1454 		pr_info_once(
1455 			"bpf-jit: not supported: atomic operation %02x ***\n",
1456 			insn->imm);
1457 		return -EFAULT;
1458 
1459 	default:
1460 		pr_err("bpf-jit: unknown opcode %02x\n", code);
1461 		return -EINVAL;
1462 	}
1463 
1464 	return 0;
1465 }
1466 
bpf_jit_build_prologue(struct hppa_jit_context * ctx)1467 void bpf_jit_build_prologue(struct hppa_jit_context *ctx)
1468 {
1469 	const s8 *tmp = regmap[TMP_REG_1];
1470 	const s8 *dst, *reg;
1471 	int stack_adjust = 0;
1472 	int i;
1473 	unsigned long addr;
1474 	int bpf_stack_adjust;
1475 
1476 	/*
1477 	 * stack on hppa grows up, so if tail calls are used we need to
1478 	 * allocate the maximum stack size
1479 	 */
1480 	if (REG_ALL_SEEN(ctx))
1481 		bpf_stack_adjust = MAX_BPF_STACK;
1482 	else
1483 		bpf_stack_adjust = ctx->prog->aux->stack_depth;
1484 	bpf_stack_adjust = round_up(bpf_stack_adjust, STACK_ALIGN);
1485 
1486 	/* make space for callee-saved registers. */
1487 	stack_adjust += NR_SAVED_REGISTERS * REG_SIZE;
1488 	/* make space for BPF registers on stack. */
1489 	stack_adjust += BPF_JIT_SCRATCH_REGS * REG_SIZE;
1490 	/* make space for BPF stack. */
1491 	stack_adjust += bpf_stack_adjust;
1492 	/* round up for stack alignment. */
1493 	stack_adjust = round_up(stack_adjust, STACK_ALIGN);
1494 
1495 	/*
1496 	 * The first instruction sets the tail-call-counter (TCC) register.
1497 	 * This instruction is skipped by tail calls.
1498 	 * Use a temporary register instead of a caller-saved register initially.
1499 	 */
1500 	emit(hppa_ldi(MAX_TAIL_CALL_CNT, HPPA_REG_TCC_IN_INIT), ctx);
1501 
1502 	/*
1503 	 * skip all initializations when called as BPF TAIL call.
1504 	 */
1505 	emit(hppa_ldi(MAX_TAIL_CALL_CNT, HPPA_REG_R1), ctx);
1506 	emit(hppa_bne(HPPA_REG_TCC_IN_INIT, HPPA_REG_R1, ctx->prologue_len - 2 - HPPA_BRANCH_DISPLACEMENT), ctx);
1507 
1508 	/* set up hppa stack frame. */
1509 	emit_hppa_copy(HPPA_REG_SP, HPPA_REG_R1, ctx);			// copy sp,r1 (=prev_sp)
1510 	emit(hppa_ldo(stack_adjust, HPPA_REG_SP, HPPA_REG_SP), ctx);	// ldo stack_adjust(sp),sp (increase stack)
1511 	emit(hppa_stw(HPPA_REG_R1, -REG_SIZE, HPPA_REG_SP), ctx);	// stw prev_sp,-0x04(sp)
1512 	emit(hppa_stw(HPPA_REG_RP, -0x14, HPPA_REG_SP), ctx);		// stw rp,-0x14(sp)
1513 
1514 	REG_FORCE_SEEN(ctx, HPPA_REG_T0);
1515 	REG_FORCE_SEEN(ctx, HPPA_REG_T1);
1516 	REG_FORCE_SEEN(ctx, HPPA_REG_T2);
1517 	REG_FORCE_SEEN(ctx, HPPA_REG_T3);
1518 	REG_FORCE_SEEN(ctx, HPPA_REG_T4);
1519 	REG_FORCE_SEEN(ctx, HPPA_REG_T5);
1520 
1521 	/* save callee-save registers. */
1522 	for (i = 3; i <= 18; i++) {
1523 		if (OPTIMIZE_HPPA && !REG_WAS_SEEN(ctx, HPPA_R(i)))
1524 			continue;
1525 		emit(hppa_stw(HPPA_R(i), -REG_SIZE * (8 + (i-3)), HPPA_REG_SP), ctx);	// stw ri,-save_area(sp)
1526 	}
1527 
1528 	/*
1529 	 * now really set the tail call counter (TCC) register.
1530 	 */
1531 	if (REG_WAS_SEEN(ctx, HPPA_REG_TCC))
1532 		emit(hppa_ldi(MAX_TAIL_CALL_CNT, HPPA_REG_TCC), ctx);
1533 
1534 	/*
1535 	 * save epilogue function pointer for outer TCC call chain.
1536 	 * The main TCC call stores the final RP on stack.
1537 	 */
1538 	addr = (uintptr_t) &ctx->insns[ctx->epilogue_offset];
1539 	/* skip first two instructions of exit function, which jump to exit */
1540 	addr += 2 * HPPA_INSN_SIZE;
1541 	emit(hppa_ldil(addr, HPPA_REG_T2), ctx);
1542 	emit(hppa_ldo(im11(addr), HPPA_REG_T2, HPPA_REG_T2), ctx);
1543 	emit(EXIT_PTR_STORE(HPPA_REG_T2), ctx);
1544 
1545 	/* load R1 & R2 from registers, R3-R5 from stack. */
1546 	/* use HPPA_REG_R1 which holds the old stack value */
1547 	dst = regmap[BPF_REG_5];
1548 	reg = bpf_get_reg64_ref(dst, tmp, false, ctx);
1549 	if (REG_WAS_SEEN(ctx, lo(reg)) | REG_WAS_SEEN(ctx, hi(reg))) {
1550 		if (REG_WAS_SEEN(ctx, hi(reg)))
1551 			emit(hppa_ldw(-0x48, HPPA_REG_R1, hi(reg)), ctx);
1552 		if (REG_WAS_SEEN(ctx, lo(reg)))
1553 			emit(hppa_ldw(-0x44, HPPA_REG_R1, lo(reg)), ctx);
1554 		bpf_put_reg64(dst, tmp, ctx);
1555 	}
1556 
1557 	dst = regmap[BPF_REG_4];
1558 	reg = bpf_get_reg64_ref(dst, tmp, false, ctx);
1559 	if (REG_WAS_SEEN(ctx, lo(reg)) | REG_WAS_SEEN(ctx, hi(reg))) {
1560 		if (REG_WAS_SEEN(ctx, hi(reg)))
1561 			emit(hppa_ldw(-0x40, HPPA_REG_R1, hi(reg)), ctx);
1562 		if (REG_WAS_SEEN(ctx, lo(reg)))
1563 			emit(hppa_ldw(-0x3c, HPPA_REG_R1, lo(reg)), ctx);
1564 		bpf_put_reg64(dst, tmp, ctx);
1565 	}
1566 
1567 	dst = regmap[BPF_REG_3];
1568 	reg = bpf_get_reg64_ref(dst, tmp, false, ctx);
1569 	if (REG_WAS_SEEN(ctx, lo(reg)) | REG_WAS_SEEN(ctx, hi(reg))) {
1570 		if (REG_WAS_SEEN(ctx, hi(reg)))
1571 			emit(hppa_ldw(-0x38, HPPA_REG_R1, hi(reg)), ctx);
1572 		if (REG_WAS_SEEN(ctx, lo(reg)))
1573 			emit(hppa_ldw(-0x34, HPPA_REG_R1, lo(reg)), ctx);
1574 		bpf_put_reg64(dst, tmp, ctx);
1575 	}
1576 
1577 	dst = regmap[BPF_REG_2];
1578 	reg = bpf_get_reg64_ref(dst, tmp, false, ctx);
1579 	if (REG_WAS_SEEN(ctx, lo(reg)) | REG_WAS_SEEN(ctx, hi(reg))) {
1580 		if (REG_WAS_SEEN(ctx, hi(reg)))
1581 			emit_hppa_copy(HPPA_REG_ARG3, hi(reg), ctx);
1582 		if (REG_WAS_SEEN(ctx, lo(reg)))
1583 			emit_hppa_copy(HPPA_REG_ARG2, lo(reg), ctx);
1584 		bpf_put_reg64(dst, tmp, ctx);
1585 	}
1586 
1587 	dst = regmap[BPF_REG_1];
1588 	reg = bpf_get_reg64_ref(dst, tmp, false, ctx);
1589 	if (REG_WAS_SEEN(ctx, lo(reg)) | REG_WAS_SEEN(ctx, hi(reg))) {
1590 		if (REG_WAS_SEEN(ctx, hi(reg)))
1591 			emit_hppa_copy(HPPA_REG_ARG1, hi(reg), ctx);
1592 		if (REG_WAS_SEEN(ctx, lo(reg)))
1593 			emit_hppa_copy(HPPA_REG_ARG0, lo(reg), ctx);
1594 		bpf_put_reg64(dst, tmp, ctx);
1595 	}
1596 
1597 	/* Set up BPF frame pointer. */
1598 	dst = regmap[BPF_REG_FP];
1599 	reg = bpf_get_reg64_ref(dst, tmp, false, ctx);
1600 	if (REG_WAS_SEEN(ctx, lo(reg)) | REG_WAS_SEEN(ctx, hi(reg))) {
1601 		if (REG_WAS_SEEN(ctx, lo(reg)))
1602 			emit(hppa_ldo(-REG_SIZE * (NR_SAVED_REGISTERS + BPF_JIT_SCRATCH_REGS),
1603 				HPPA_REG_SP, lo(reg)), ctx);
1604 		if (REG_WAS_SEEN(ctx, hi(reg)))
1605 			emit_hppa_copy(HPPA_REG_ZERO, hi(reg), ctx);
1606 		bpf_put_reg64(dst, tmp, ctx);
1607 	}
1608 
1609 	emit(hppa_nop(), ctx);
1610 }
1611 
bpf_jit_build_epilogue(struct hppa_jit_context * ctx)1612 void bpf_jit_build_epilogue(struct hppa_jit_context *ctx)
1613 {
1614 	__build_epilogue(false, ctx);
1615 }
1616